how to make this cylinder model with holes
Create a cylynder, and subdivide it the number of times right to have one hole in every column; then add (CTRL R) some loop cut just to have square faces; select every face corresponding with the holes (you can try the checker deselect function) and delete them (X, Enter).

Then add a subsurf modifier, and you'll have your holes.

You can improve the mesh with a solidify modifier and playing with edge creases.

A lot of functions you use in edit mode have their parameters regulation in the "T" panel, left-down the 3D Window, as shown in the picture.